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!20 Fix relocation not resolved when new functions exported only

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From: @xiezhipeng1
Reviewed-by: @licihua
Signed-off-by: @licihua
This commit is contained in:
openeuler-ci-bot 2020-12-31 10:40:52 +08:00 committed by Gitee
commit 1c57d74dda
2 changed files with 137 additions and 1 deletions
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129
0025-Fix-relocation-not-resolved-when-new-functions-expor.patch Normal file
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@ -0,0 +1,129 @@
From 737ab3efcde45cde5fbe43ee977fc18b6912f356 Mon Sep 17 00:00:00 2001
From: Zhipeng Xie <xiezhipeng1@huawei.com>
Date: Sun, 22 Nov 2020 21:40:39 +0800
Subject: [PATCH] Fix relocation not resolved when new functions exported only
When no functions changed and new functions exported, kobject is not
created, so livepatch will not call klp_init_object and relocation
in new functions are not resolved.
Signed-off-by: Zhipeng Xie <xiezhipeng1@huawei.com>
---
kmod/patch/kpatch-patch.h | 4 ++++
kmod/patch/kpatch.lds.S | 6 ++++++
kmod/patch/livepatch-patch-hook.c | 19 +++++++++++++++++++
kpatch-build/create-diff-object.c | 24 ++++++++++++++++++++++++
4 files changed, 53 insertions(+)
diff --git a/kmod/patch/kpatch-patch.h b/kmod/patch/kpatch-patch.h
index 6e39364..33f2056 100644
--- a/kmod/patch/kpatch-patch.h
+++ b/kmod/patch/kpatch-patch.h
@@ -63,6 +63,10 @@ struct kpatch_post_unpatch_callback {
void (*callback)(void *obj);
char *objname;
};
+struct kpatch_object {
+ char *objname;
+};
extern unsigned long __kpatch_force_funcs[], __kpatch_force_funcs_end[];
+extern struct kpatch_object __kpatch_objects[], __kpatch_objects_end[];
#endif /* _KPATCH_PATCH_H_ */
diff --git a/kmod/patch/kpatch.lds.S b/kmod/patch/kpatch.lds.S
index bc5de82..4c4d77b 100644
--- a/kmod/patch/kpatch.lds.S
+++ b/kmod/patch/kpatch.lds.S
@@ -47,4 +47,10 @@ SECTIONS
__kpatch_force_funcs_end = . ;
QUAD(0);
}
+ .kpatch.objects : {
+ __kpatch_objects = . ;
+ *(.kpatch.objects)
+ __kpatch_objects_end = . ;
+ QUAD(0);
+ }
}
diff --git a/kmod/patch/livepatch-patch-hook.c b/kmod/patch/livepatch-patch-hook.c
index 5a0de7f..d3fb1db 100644
--- a/kmod/patch/livepatch-patch-hook.c
+++ b/kmod/patch/livepatch-patch-hook.c
@@ -249,6 +249,22 @@ static int patch_is_func_forced(unsigned long addr)
return 0;
}
+static int add_kpatch_objects(void)
+{
+ struct kpatch_object *p_kpatch_object;
+ struct patch_object *object;
+
+ for (p_kpatch_object = __kpatch_objects;
+ p_kpatch_object < __kpatch_objects_end;
+ p_kpatch_object++) {
+ object = patch_find_object_by_name(p_kpatch_object->objname);
+ if (!object)
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
#ifdef HAVE_CALLBACKS
static int add_callbacks_to_patch_objects(void)
@@ -382,6 +398,9 @@ static int __init patch_init(void)
if (ret)
goto out;
+ ret = add_kpatch_objects();
+ if (ret)
+ goto out;
/* past this point, only possible return code is -ENOMEM */
ret = -ENOMEM;
diff --git a/kpatch-build/create-diff-object.c b/kpatch-build/create-diff-object.c
index fca68b8..bea758e 100644
--- a/kpatch-build/create-diff-object.c
+++ b/kpatch-build/create-diff-object.c
@@ -2553,6 +2553,27 @@ static void kpatch_create_kpatch_arch_section(struct kpatch_elf *kelf, char *obj
karch_sec->sh.sh_size = karch_sec->data->d_size;
}
+static void kpatch_create_kpatch_object_section(struct kpatch_elf *kelf, char *objname)
+{
+ struct symbol *strsym;
+ struct rela *rela;
+ struct section *kobj_sec;
+
+ kobj_sec = create_section_pair(kelf, ".kpatch.objects", sizeof(struct kpatch_object), 1);
+
+ /* lookup strings symbol */
+ strsym = find_symbol_by_name(&kelf->symbols, ".kpatch.strings");
+ if (!strsym)
+ ERROR("can't find .kpatch.strings symbol");
+
+ /* entries[index].objname */
+ ALLOC_LINK(rela, &kobj_sec->rela->relas);
+ rela->sym = strsym;
+ rela->type = absolute_rela_type;
+ rela->addend = offset_of_string(&kelf->strings, objname);
+ rela->offset = (unsigned int)(offsetof(struct kpatch_object, objname));
+}
+
static void kpatch_process_special_sections(struct kpatch_elf *kelf)
{
struct special_section *special;
@@ -3710,6 +3731,9 @@ int main(int argc, char *argv[])
kpatch_create_intermediate_sections(kelf_out, lookup, parent_name, patch_name);
kpatch_create_kpatch_arch_section(kelf_out, parent_name);
kpatch_create_callbacks_objname_rela(kelf_out, parent_name);
+ if (!num_changed && new_globals_exist) {
+ kpatch_create_kpatch_object_section(kelf_out, parent_name);
+ }
kpatch_build_strings_section_data(kelf_out);
gcc_add_option = getenv("GCC_ADD_OPTION");
--
2.18.1

9
kpatch.spec
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@ -1,7 +1,7 @@
Name: kpatch
Epoch: 1
Version: 0.9.1
Release: 7
Release: 8
Summary: A Linux dynamic kernel patching infrastructure
License: GPLv2
@ -36,6 +36,7 @@ Patch0021:0021-kpatch-build-don-t-copy-.config-for-out-of-tree-modu.patch
Patch0022:0022-support-force-enable-disable-for-x86.patch
Patch0023:0023-create-diff-object-fix-duplicate-symbols-for-vmlinux.patch
Patch0024:0024-optimize-for-out-of-tree-module.patch
Patch0025:0025-Fix-relocation-not-resolved-when-new-functions-expor.patch
BuildRequires: gcc elfutils-libelf-devel uname-build-checks kernel-devel git
Requires: bc
@ -95,6 +96,12 @@ popd
%{_mandir}/man1/*.1.gz
%changelog
* Sun Nov 22 2020 Zhipeng Xie<xiezhipeng1@huawei.com> -1:0.9.1-8
- Type:bugfix
- ID:NA
- SUG:NA
- DESC:Fix relocation not resolved when new functions exported only
* Tue Nov 17 2020 Zhipeng Xie<xiezhipeng1@huawei.com> -1:0.9.1-7
- Type:enhancement
- ID:NA